300,000 adolescent girls have had a series of lessons designed to break taboos - but teachers also have to be persuaded to end their prejudices about periods.
After attending a menstruation myth-busting class in her village in India, 13-year-old Dhanashree Kantaram Dhere decided to test her newfound knowledge by touching a statue of a Hindu god in her family home.
Although it was believed to be bad luck, nothing terrible happened.
According to widely-held beliefs in India, menstruating women are impure and should not enter temples, take part in religious ceremonies, or prepare certain foods, among other restrictions.
Those taboos are being challenged in states including Maharashtra, where the government late last year ordered all public schools to begin teaching the truth about periods.
Dhere began menstruating four months ago - but unlike many women in India she was taught that it was healthy. Her mother was not convinced though and refused to let her help prepare papadums, which are thin, crispy, cracker-like snacks.
"I learned in school that nothing would happen if I touched food, so I did," she recalled. "But I was worried and watched. Nothing happened."
Emboldened with her first experiment, Dhere decided to test the taboo further.
"So, I also touched a god's idol after that," she said.
The admission drew gasps from fellow students, who were discussing menstruation at their school in Kheware Mehaj, a small village about 90 miles from Mumbai.
They are among the 300,000 adolescent girls who have taken classes during the past two years in seven Maharashtra districts, according to Yusuf Kabir of the United Nations children's agency UNICEF.
UNICEF started the menstrual hygiene programme five years ago in Maharashtra's Jalna and Aurangabad districts and is now partnered with the government to expand it to schools across the state.
Two years ago, the federal government incorporated the programme into its Clean India Mission, which aims to clean up streets and roads in communities throughout the country.
Vennelaganti Radha, joint secretary in the federal Ministry of Drinking Water and Sanitation, said the menstrual hygiene programme is now being implemented in other states in partnership with various non-governmental organisations.
"But Maharashtra is a leader in this," she said. "UNICEF and local officials have done great work."
The first challenge is the teachers, who are in charge of incorporating the class into the curriculum. Trainers from UNICEF have to convince them that there is nothing unclean about menstruation.
Around 80% of the teachers believed that menstrual blood is impure.
"The teachers had a lot of inhibitions and believed the myths themselves," said Bharathy Tahiliani, a rights campaigner who drafted the menstruation lesson plans.
"Around 80% of the teachers believed that menstrual blood is impure," she told the Thomson Reuters Foundation.
She said it takes multiple training sessions to get them comfortable talking to students about their own menstruation experiences.
Once they are ready, teachers begin running the programme over the course of six months. The students are all female except for one session in which boys watch an educational video.
In addition to traditional textbook learning, the course includes games, songs and drama.
The course is desperately needed, according to Tarulata Dhanke, a physician and government health officer who worked for 14 years in a village in Maharashtra and is now overseeing the programme's implementation in Thane district.
"I would get girls seeking stitches in their vagina when they first got their period," she said. "They had no idea why they were bleeding suddenly."
Those raising awareness across India will soon get a boost with the release of PadMan, a film scheduled for release next week in which a popular action hero uses a sanitary pad to fight discrimination faced by women during their periods.
In addition to helping girls feel good about getting their periods, the lessons may convince them to stay in school and save them from sickness.
Periods are among the leading factors for girls to drop out of school, often to get married early. It is also common to skip school during menstruation, largely due to lack of toilets or safe places to change their pads.
Studies have shown the vulnerability of menstruating women to infections of the urinary and reproductive tract due to unhygienic practices.
This is partly due to unhygienic methods of cleaning cloth, which is used by more than 60% of Indian women aged 15 to 24 during their periods, according to recent government data.
Pads are not easily available in many rural parts of the country but taboos around menstruation mean that women are ashamed to openly wash and dry cloth.
Health experts say that can lead to infection, because the cloth needs to be dried in direct sunlight in order more effectively to kill germs.
Harshala Anil Suroshe, 13, said she used to hide her "period cloth" after washing it "so nobody could see". But that has changed since her she began the menstrual hygiene lessons at school.
"After use, I wash the cloth and dry it in the sun," she said. "I showed my mother and sister too that this is how it is done."